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3:05 PM

Hello, I asked this question earlier, but I was too tired to read the response. So I am posting again because there are a few things that are confusing me conceptually and re: what my professor is wanting so I am reposting

I really want to fully understand it before I proceed

I am trying to solve a transition matrix type problem.

I have the following system of equations:

0.8x1 + 0 + 0.3x3 = 0.36

0.2x1 + 0.9x2 + 01.x3 = 0.37

0 + 0.1x2 + 0.6x3 = 0.27

I have already put it into a 3x3 matrix and into an equation of form AX = b, where b is vector b =[0.36, 0.37, 0.27].

Part of the problem is to work out the values of x1, x2, x3, as they currently are which are 0.3, 0.3, and 0.4.

The next part we have to find use this same equation to find the same values where the distribution remains the same across the years. From our materials to me that the this can be cal…

So I am aware that we can solve this using the method (A-I) = 0, but our professor does not want this method

so the method I am actually slightly confused about and people are saying different things, he is saying that he wants to insert a row of zeroes at the bottom of the matrix in solving this ...

but I don't know what he means by that

Maybe it'd help if I post the matrix I need to get to ...

user21820

@MEcho If you're unable to reproduce what exactly your professor said, I'm afraid I don't want to spend time figuring out, simply because there is absolutely nothing wrong with the way we had discussed; to solve (A−I)x = 0 for non-zero x.

MEcho

I think that's being a little ungenerous

Jesus

user21820

This room is about mathematics, not satisfying teachers, and I have finite time, so I do not wish to spend unnecessary time on non-math in here. You are of course welcome to try other chat-rooms.

Also please do not swear in this chat-room in any fashion.

MEcho

It's not non math

It's possible that there is more than one method of solving this problem?

user21820

@MEcho I very clearly said "IF you're unable to reproduce what exactly your professor said".

If you can exactly reproduce what your professor said, we can look at it.

But if you cannot, I will not waste time trying to figure out something nebulous and unnecessary.

The method we discussed is the best method, so there is no reason to look for another.

MEcho

3:14 PM

Alright i'll post it verbatim

user21820

Sure.

MEcho

All I need to do is arrive at the matrix -

Perhaps this might help.

Solving each equation individually is equivalent to defining a plane floating in 3-d space. Solving the system of equations simultaneously is equivalent to finding the locus of points in space where all these planes intersect.

In part (a) the first three equations of the system are sufficient to intersect in a single point - which is the unique solution of the system. This unique point also satisfies the fourth equation, which means that if we had intersected all four planes in space we would still end up with the same common point of intersection.

Gauss-Jordan is the method, but we have been asked to arrive at matrix A-I by subtracting the respective values from x, y, z in each row to arrive at A-I, and it's not working for, and I dont understand what I'm doing wrong.

user21820

@MEcho I see no relation between what is stated there and the original question: "find the same values where the distribution remains the same across the years.".

MEcho

You are not trying to be helpful

user21820

That's false.

I really see no relation.

Look, I tried to help you, but you are rude and ungrateful. Please leave.

user21820

4:14 PM

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